The present invention relates to a powder supply device for a powder coating system.
The device according to the invention is particularly suitable for supplying powder to a powder coating system used to electrostatically spray coat objects in which fresh coating powder (hereinafter also called “fresh powder”) and, as applicable, reclaimed coating powder (hereinafter also called “recovered powder”) is situated in the powder container and is supplied to a powder dispensing mechanism of a spraying device. The spraying device can be designed for example as a manual spray gun or an automatic spray gun.
A powder injector is normally used as the powder dispensing mechanism. It is thereby provided for compressed air from the feed air connection of the powder injector to be pushed through a venturi nozzle into the collector nozzle. On its way through the powder injector, the feed air passes across a powder suction tube connected to the powder container at which point coating powder is sucked out of the powder container due to the negative pressure.
The powder container is thereby fed fresh powder as needed via a fresh powder line from a supplier's container with which the powder supplier supplied the fresh powder to the powder user. The powder forms a compact mass in the supplier's container. By contrast, the coating powder should be in a fluidized state in the powder container so that it can be for example pumped out by the suction effect of the powder dispensing mechanism (powder injector) and be fed to the spraying device as a flow of powder. A powder supply device therefore in particular comprises a powder container serving as a powder chamber for storing coating powder, wherein the coating powder is normally fluidized in the powder container so that it can be more easily conveyed pneumatically to either another powder container or to a powder spraying device.
As already indicated, the powder spraying device can be a manual or automatic powder spraying device which can have a spray nozzle or a rotary atomizer.